I am looking for information regarding the way various designers specify copper thickness for boards, and how this information is translated by the manufacturers. IPC-D-325A and IPC-D-275 are not clear on how this information is to be stated or translated. We have always indicated the copper weight as the starting weight, ie. 2oz, 1oz, 1/2oz, etc.. Some manufacturers translate this designation as finished weight. They will start with a lighter copper and plate up to a finished dimension, (start with 1oz, plate up to 2oz). Tolerances are not stated in the IPC documents. IPC-RB-276 indicates that, in the case of 2oz copper, the finished surface thickness should be .003". What is the general direction of the industry? As indicated above, I have had manufacturers indicate both ways. Rich Ackerson Sr. Industrial Engineer Elsag Bailey Electronics Voice 216-585-7646 Fax 216-585-8867 [log in to unmask] or [log in to unmask]